Armchair



FIG. 1 is a front view of the armchair of the claimed design;

FIG. 2 is a left perspective view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

CLAIM I claim the ornamental design for armchair, as shown and described. 